Such an electrically caged, dynamically tuned gyro having two input axes which are orthogonal to each other is described in DE-A1-30 33 281. There, the motor is arranged in a part of a case which is separated by means of a partition from a part of a case containing the gyro rotor. An arrangement of bearings for the motor shaft sits in the partition. The gyro rotor contains an annular groove in its end face facing the partition, with the sidewalls of this groove being formed by radially magnetized rings. Pairs of diametrically opposed flat coils curved along a cylinder surface extend into this annular groove. The flat coils, in conjunction with the rings, form the torquers. The pick-offs are formed by coils, which sit on the partition and cooperate with the end face of the gyro rotor. The signals of the pick-offs are applied cross-wise to the torquers via analog caging circuits. A differentiating damping network for the damping of nutational oscillations is also provided in DE-A1-30 33 281.
Similarly constructed, electrically caged, dynamically tuned gyros are illustrated and described in DE-A1-28 34 379, as well as DE-B2-24 29 913 and DE-C-12 81 216.
In the EP-A2-0 251 157, an inertial detector arrangement having an electrically caged, dynamically tuned gyro is described in which the caging circuit operates digitally.
The DE-C2-32 13 720 shows a dynamically suspended gimbal suspension having two degrees of freedom.
U.S. Pat. No. 3,702,569 describes a gyro with a rotor which is driven by a motor through a flexible joint. The peripheral portion of the rotor is made of magnetic material and forms an annular channel having an inverted U-shape cross section. A ring type permanent magnet polarized at its inner and outer peripheries is mounted on the inner peripheral wall of the channel. Torquer coil windings are embedded in an insulating cylinder that extends partially into the annular air gap formed between the outer channel wall and the ring magnet.
A similar design is shown in German patent 3,344,315.
German patent 3,519,891 discloses a gyro the rotor of which is rotatably mounted on a shaft which, in turn, is adapted for swivelling movement by means of flexible joints. The rotor is driven by a spring or fluid motor. A hat-shaped structure carrying a ring of magnetic material below its "rim" is arranged on the swivelling shaft inside the rotor and does not rotate with the rotor. The ring is arranged in front of the end face of the rotor, axial torquer coils cooperate with this ring to exert torques on the rotor.